Re: HTML <h5 class="unnumberedsubsubsec"> too small

[Stephen Gildea]

I'm not comfortable with breaking the level association of Texinfo to
HTML just because some browsers (okay, most browsers) display H5 and H6
tags poorly.  HTML output should be about structure.

Style Sheets are about presentation, so that seems to me a better place
to fix the offending headers.  That would mean merely adding the
following to the head of an HTML document:

<style type="text/css"><!--
  h5, h6 { font-size: medium; }
--></style>

Or if that is still too small for you, use this instead:

<style type="text/css"><!--
  h4, h5, h6 { font-size: large; }
--></style>